Aganisia, Lindley

Thiago E. C. Meneguzzo, José F. A. Baumgratz & Cássio Van Den Berg, 2015, Taxonomic studies in the Aganisia complex (Orchidaceae, Zygopetalinae), Phytotaxa 238 (1), pp. 1-39 : 3-4

The Aganisia Complex:

— The group can be recognized by the following characteristics: epiphytic, hemiepiphytic or terrestrial, rarely rupiculous herbs, with inconspicuous, homoblastic, ovoid or fusiform pseudobulbs, with cataphylls at their base, leafy or not, scarious or not. There are one to four leaves in the distal portion of the pseudobulb. The petiole is articulate, conduplicate, distinct from the blade, margin hyaline or not, which usually is plicate and provided with more prominent nerves in the abaxial surface. The inflorescence usually is taller than the plant and erect, rarely shorter and arching.

Flowering is acropetal, and each flower has a single bract that always is shorter than the ovary. The dorsal sepal and petals are always free, and lateral sepals are adnate to a column foot. The lip is free, not firmly attached, trilobed, unguiculate, entire, always with a basal central callus. The foot usually is shorter than the column, the latter with a pair of stigmatic wings. The anther is incumbent, and the margin of the clinandrium is entire, rarely projecting over the anther. The external face of the anther cap is usually bilobed but can also be entire, the apex obtuse, denticulate or digitiform. The pollinarium has four juxtaposed pollinia, subequal in size, the inner pair smaller than the outer. They attached by a tegula, caudicle and viscidium. The stigma is transverse, the rostellum entire or trilobed, never exceeding the stigma. The capsule is fusiform, with six ridges with a smooth or verrucose surface.

Key to genera of the Aganisia complex

1 Leaves conduplicate ......................................................................................................................................................... Cheiradenia

- Leaves plicate .....................................................................................................................................................................................2

2 Plants rhizomatous; pseudobulbs covered by scarious cataphylls ........................................................................................ Aganisia

- Plants caespitose; pseudobulbs not covered by scarious cataphylls...................................................................................................3

3 Pseudobulbs covered by leafy, articulate cataphylls; petiole margin hyaline; lip callus hippocrepiform; stigmatic wings conspicuous.......................................................................................................................................................................................... Otostylis

- Pseudobulbs covered by non-leafy, non-articulate cataphylls; petiole margin non-hyaline; lip callus 2(–3)-lobed or semi-conical; stigmatic wings inconspicuous ...........................................................................................................................................................4

4 Lip with prominent lateral lobes, callus 2(–3)-lobed .................................................................................................... Koellensteinia

- Lip with strongly reduced lateral lobes, callus semi-conical ....................................................................................... Paradisanthus